Transformer apparatus



W. REICHE TRANSFQRMER APPARATUS Filed May 29, 1930 Patented Dec. 12, 1933 wuu male, Dresden,

Koch a Sterne! Aktlcngeaelllchaft,

Germany, assignor to Dresden,

Germany, a German columns Application May 29, 1930, Serial No. 457,185 inGermanyMay3Ll923 e 1 Claim. (01.171419) This invention relates to tapp n arrangements for step transformers with a stepless regulating transformer having a sub-divided energizing winding in which the tappings are combined into 6 groups connected to correspond to the subdivision of said energizing winding, so that upon connection of two adjacent tapping groups, a tapping is common to said groups, whereby the induction flux of the regulating transformer is maintained 10 at the same magnitude but becomes of opposite direction.

Arrangements are already known for gradually altering the potential over the consecutive stages of an auto transformer by means of an induction regulator and, for this purpose, there has been used a rotary transformer comprising two concentric members, one rotatable within the other,. and having windings embedded therein giving uniform variation of potential when connected between the separate stages. Recently it has become known to use with such a tapping connection device a so-called sliding core transformer as the induction regulator. This transformer has a secondary winding embedded in slots on a stationary iron core, and an energizing winding divided into two sections and carried on a movable iron core, one or other of said sections of the energizing winding either wholly or partly surrounding the secondary winding. Since the 80 movable iron core is displaced along the fixed iron core, there takes place a continuous variation ,of potential at the terminals of the secondary winding. The connection of the sliding core transformer with the auto transformer is obtained by tappings (11, 12, 13)arranged in groups (11, 13 and 12, 13) connected to correspond to the sub-division of the energizing winding, so that upon switching from one group to another, one tapping (13) is common to two adjacent tapping groups, whereby the induction flux of the supplementary transformer (20) remains of the same value but is given an opposite direction.

With very high potentials it is however not economical to arrange the sliding core transformer for direct connection in the mains, by reason of the large amount of insulation required in the winding slots, although it is already known when using a rotary regulating transformer to separate the regulator electrically from the mains by means of insulating transformers.

The invention has reference to regulating apparatus of the above type for high potentials and has for its object to obviate the necessity for the use of heavy insulation in the winding slots of the induction regulator. To this end, according to the invention, the induction regulator is itself insulated from earth, the regulated output potential therefrom being impressed on ,the mains through a supplementary isolating transformer connected in the line.

With this arrangement the use of a large quantity of insulation in the winding slots of an induction regulator of the sliding core type connected to the auto-transformer is unnecessary, the insulation instead being transferred to the 95 external fixing parts of said regulator, which insulation carries the total mains potential.

The induction regulator is thus completely ine sulated and the secondary winding connected in the mains line need only be provided within its 7 slots with slight insulation. The isolating transformer requires only relatively slight insulation suificient to resist the surge potential, since as already stated, the insulated mounting of the induction regulator serves to take the mains potential.

In the single figure of the accompanying diagrammatic drawing, the invention is shown as an example in the connection just described. 18 is the tapped winding of the auto transformer, and 11, 12, 13 are the' tappings. 20 is the sliding core induction regulator having a divided energizing winding, said regulator being mounted on insulators 30, and 38 is the supplementary transformer situated in the line. The regulator 20 comprises an iron core 39 having wound thereon, and in fixed relation thereto, a winding 23. Exteriorly disposed about this core are two windings 21, 22 which are oppositely connected in parallel, and are wound so as to be movable together with 90 respect to the stationary winding 23. U1 is the constant potential, and U: the potential regulated to any desired value. In the arrangement shown, the tappings 11, 12 and 13 are so grouped that the tapping 13 is common to both portions of the 5 winding 18. Current passing from one line through the tapping 13 flows through the two portions 21, 22 of the energizing winding. If now switch 14 at the tapping 11 is closed and assuming the windings of the regulator 20'to be in the position shown in the drawing, the potential Us is equal to the input potential U1. 1! then the secondary winding 23 is moved in the direction of the arrow to, for example, the central position, the potential U: will be increased to that at the tapping 11. If the secondary winding 23 is moved to its lowermost position, the potential U: will again be increased by an amount equal to the first increase, that is, by twice the difi'erence of potential between the toppings 13, 11. If, instead '12 is closed, the output potential U: will be reduced to the same extent when the winding 23 is varied in the above described manner. If it is desired, this arrangement can also be so arranged that Us is the incoming potential fluctuating to any extent, while U1 is the outgoing potential regulated to a constant value.

In one position, only the upperzwin'ding 22 induces an E. M. F. in the winding 23, the trans formation ratio corresponding to the ratio 01' the turns comprising said windings. In this position, the winding 21 is out of operation but as the element carrying the windings 21 and 22 is moved upwardly to a position wherein the lower portion of the winding 22 and the upper portion of the winding 21 are opposite the winding 23, the E. M. F. induced in the winding 23 by the winding 22 is gradually reduced, while that induced by the winding 21 is gradually increased. Finally, when the winding 21, is positioned directly opposite the winding 23 and the winding 22 is entirely above the winding 23, the winding 21 induces an E. M. F. in the winding 23 equal to that induced by the winding 22 in the intermediate position just described, but of opposite sense. In the final position, the winding 22 is inoperative.

The drawing shows the circuit diagram for single phase current, but the use of the arrangement may be easily applied to multiple phase current. In this case, the iron cores of the sliding core induction regulator are, of course, not only to be, insulated with respect to earth, but the iron cores corresponding to the different phases must also be insulated with respect to each other.

I claim:

Apparatus for the regulation of high potentials in a line 01' the type comprising an auto-transformer, having a plurality of taps, an induction regulator insulated from earth and having relatively movable primary and secondary windings,

the primary winding being divided to be variably connected to the taps oi the auto-transformer, and a supplementary transformer connected in the line and to said secondary winding and regulating the output potential from the induction regulator.

WILLI REICHE. 

